Vapor power plant

ABSTRACT

A vapor power plant driven with a working fluid vaporized from a liquid having a relatively freezing point such as trichloromonofluoromethane, comprising a working fluid circuit and a cooling fluid circuit both of which share limited common a passage with each other so that the same liquid can be used both as a working medium for driving a prime mover of the power plant and as a cooling medium for cooling an exhaust from the prime mover.

United States Patent Maeda 1151 3,675,416 1451 July 11, 1972 $41 VAPORPOWER PLANT [72] Inventor: Rllehl Meet, Yokohama. Japan [73I Anignee:

[22] Filed:

[2|] Appl.No.: 71,033

[30] Foreign Application Priority Duh Sept. 18, I969 Japan ..44/7357560/ 60/94. 60/95 ...F0ll1 25/08, FOlk l9/l0 ..60/36, 95, 39, 40, 94

[56] Relu'eneeg Cited UNITEDSTATES PATENTS 3,557,554 l/l97l Mal-tine]:e! a] ..60/95 R X Pn'maq- Examiner-Martin P. Schwadmn Assistantxaminer-Allen M. Clinger Auomey-Mdlarthy, Depaoli. O'Brien & PriceABSTRACT A vapor power plant driven with a working fluid vaporized froma liquid having a relatively freezing point such as thane, comprising aworking fluid cir P'AT'ENTEDJUL 11 m2 3,575,415

INVENTOR AH CHI MAE DA ATTORNEYS VAPOR rowan PLANT This inventionrelates to a vapor power plant driven with vaporized working fluid andmore particularly to a method and apparatus therefore of cooling from aprime mover of such power plant.

A vapor power plant has been proposed and put into limited practice soas to supersede conventional internal combustion engines from whichnoxious compounds such as carbon monoxides, hydrocarbons and nitrogenoxides are emitted to the atmosphere causing serious air pollutionproblems where the internal combustion engines are used in motorvehicles. The vapor power plant, which is a variant of externalcombustion engines, is driven with a working fluid which is vaporizedfrom a cool liquid. lf, in this instance, it is not desired foreconomical reasons to have an exhaust from the prime mover dischargedinto the open air, the exhaust should be repeatedly cooled and recycledin a closed circuit to drive the prime mover continuously. Where watervapor is to be utilized as such a working fluid, difliculties areencountered in that the water tends to freeze in chilly weather toeventually destroy the working circuit of the power plant and in that,where the exhaust is forcedly air cooled, a large-sized, spacetakingcooling unit should be used to compensate for the low thermalconductivity between the water vapor and air.

An object of the invention is therefore to provide an improved method ofcooling exhaust from a vapor power plant in which the exhaust is freefrom freezing even in chilly weathers.

Another object of the invention is to provide an improved method ofcooling exhaust from a prime mover of a vapor power plant with anincreased performance efficiency and with use of a compact and effectivecooling unit.

Still another object is to provide a vapor power plant having means tocool and liquefy exhaust discharged from a prime mover of a power plantfor repeated use or recycling of a working plant which, on the otherhand, is utilized as a medium for cooling the exhaust recycled.

According to one aspect of the invention, it is herein proposed to useas a working fluid for the vapor power plant those chemical compoundswhich have a freezing point lower than minus 30 C at an atmosphericpressure. The working fluid may preferably have a boiling point lowerthan 95 C.

According to another important aspect of the invention, the same liquidis utilized, on one hand, as a working fluid and, on the other hand, asa cooling medium.

The method proposed by this invention as advantageous for cooling theexhaust from the prime mover of the power plant consists of thecontinuously repeated cycles each of which comprises contacting theexhaust with forcedly cooled fluid for cooling down and liquefying theexhaust into a liquid which is mixed with the cooled liquid serving as acooling medium, vaporizing a portion of the resultant cool liquid into aworking fluid for driving the prime mover, and forcedly cooling theremaining portion of the cool liquid for contact with the exhaustdischarged successively from the prime mover, wherein the liquid usedfor both driving the prime mover and cooling the exhaust from the primemover has a freezing point lower than minus 30 C. Thus, it will bereadily appreciated that, since the cooling medium used to carry out themethod according to the invention is of a liquid phase, a relativelyhigh thermal conductivity between the exhaust and the cooling medium isavailable without use of a large-sized, space-taking cooling unit. Theuse of a liquid with a relatively low freezing point, the liquid ispractically free from freezing when cooled down even in unusually chillyweathers.

The method according to the invention is advantageously carried outthrough provision of a vapor power plant comprising a working fluidcircuit including an evaporator for vaporizing a cool liquid into avaporized working fluid and a prime mover receiving the vaporizedworking fluid from the evaporator and driven therewith, and a coolingfluid circuit including a cooling means, the working fluid and coolingfluid circuits sharing a common chamber communicating with the outletport of the prime mover and the cooling means and a common liquidreservoir communicating with the inlet ports of the evaporator and thecooling. Pumps, valves and other regulating means may be providedbetween any of the components of the thus constructed power plant.

The liquid which is advantageously operable in the method and apparatusaccording to the invention is trichloromonofluoromethane, butyl acetate,diethyl carbonate, butyl ether, O-dichlorobenzene, monobromobenzene,hexafluorobenzene, trichlorotrifluoroethane, or a mixture of two or moreof these, but other fluoroor hydrocarbons may also be used, if desired.

Preferred embodiments of apparatus carrying out the method describedabove are illustrated in the accompanying drawings in which:

FIG. 1 is a schematic diagram showing an embodiment of a vapor powerplant incorporating the improvements according to the invention; and

FIG. 2 is a view showing a modification of the power plant illustratedin FIG. I.

First referring to FIG. 1, the vapor driven power plant incorporatingthe improvements according to the invention comprises an evaporator 10which is heated by an associated buming means 11 and which vaporizes acool liquid supplied thereto. The evaporator communicates at its outletport with an inlet port of a prime mover 12 to which the working fluidvaporized in the evaporator 10 is delivered. A regulator valve 13 may beinterposed between the outlet port of the evaporator l0 and the inletport of the prime mover 12, whereby the flow rate of the vapor isadjusted as desired. The prime mover l2 communicates at its outlet portwith an inlet of a vapor condenser 14 through an exhaust passage 15,whereby the exhaust discharged from the outlet port of the prime moverI2 is fed into the condenser 14 in which the vapor is cooled andliquefied as explained later. The condenser 14, in turn, communicates atits outlet port with an inlet port of a liquid reservoir l6 and the coolliquid in the condenser 14 is passed over to the reservoir 16 fortemporary storage. The reservoir 16 communicates at its outlet port withan inlet port of the boiler 10 through a feed pump 17 so that a portionof the cool liquid in the reservoir is pumped by the feed pump 17 intothe evaporator 10 for vaporization into a working fluid. A closedworking fluid circuit is thus formed by the evaporator 10, prime moverl2, exhaust passage 15, condenser 14 and liquid reservoir 16.

The burning means which is generally represented by reference numeral 11is made up, by way of example, of a fuel storage tank 11a containingfuel therein, a fuel pump llb communicating with the fuel storage tankfor pumping out the fuel therefrom, a fuel flow regulator llc adapted toregulate the flow rate of the fuel to be passed therethrough, and aburner 11d which receives the fuel from the regulator 11: and burns thefuel to heat the evaporator 10. The burning means 11 may be arrangedotherwise insofar as the purpose of heating the boiler 10 in a selectedmanner is achieved.

The power plant shown in FIG. 1 includes another closed circuit for thecirculation and forced cooling of the liquid to cool and liquefy theexhaust introduced into the condenser 14 from the prime mover 12. Thiscooling fluid circuit comprises a circulating pump 18 which communicateswith a second outlet of the liquid reservoir 16 for pumping out aportion of the cool liquid therefrom. The pump 18 communicates with aninlet port of a cooling means or radiator l9 so that the cool liquid ispumped into the cooling means or radiator 19 and is therein forcedlycooled down. The cooling means or radiator 19, in turn, communicates atits outlet port with a second inlet of the condenser 14 through acooling liquid passage 20 whereby the liquid which has been forcedlycooled down in the cooling means or radiator 19 is drawn into thecondenser chamber 14. The cooling fluid circuit is thus formed by thereservoir 16, pump 18, cooling means or radiator 19 and condenser 14. Inother words, the drive fluid circuit and the cooling fluid loop sharethe condenser 14 and the reservoir 16 with each other so that both ofthe media for driving the prime mover I; and cooling the exhaust fromthe prime mover issue from oioriginate in a common source of liquidwhich, in this instance, is the liquid reservoir.

When, in operation, the exhaust is discharged from the outlet port ofthe prime mover l2 and introduced into the condenser 14, the exhaust isbrought into contact with the cooled liquid supplied from the coolingmeans or radiator 19 and is thereby cooled down and liquefied into thecool liquid. The thus cooled liquid is mixed with the exhaust whichtherefore exchanges heat with the cooled liquid.

The resultant cool liquid is passed over to the reservoir l6. A portionof the cool liquid drawn into the reservoir is then pumped into theevaporator in which the cool liquid is converted into a hot vapor. Themajor portion of the cool liquid in the reservoir 16 is drawn into thecooling means or radiator 19 by means of the circulating pump 18 and istherein cooled and fed into the condenser 14 for contact with theexhaust from the prime mover 12. The cooling and drive media are in thismanner recycled in the cooling and working fluid circuits continuously,joining together in the condenser 14 and reservoir 16 which are sharedby the two circuits.

The power produced by the prime mover 12 is carried to a suitable drivenmember (not shown) through an output shaft lZa. Designated by referencenumeral 190 is a fan which forcedly air cools the cooling means orradiator l9.

The constructions and operations of the components of the power plantmay be changed and modified in any desired manners as long as the basicconcept of the invention is maintained. For instance, instruments foradjusting and/or regulating the performances of the individualcomponents of the power plant may be incorporated where desired. Also,the circuit connections may be modified in a desired manner, an examplebeing shown in FIG. 2.

As illustrated in FIG. 2, a modification is made to the power plant ofFIG. I so that the evaporator 10 receives the cool liquid directly fromthe cooling means or radiator 19 through a branch passage 20a which isbranched from the cooling liquid passage 20.

Now, the fuel to be used to heat the evaporator 10 may be gaseous,liquid or solid and, moreover, the cooling means or radiator 19, whichhas been described as cooled with atmospheric air, may be cooled in anydesired manner.

It may be herein noted that emission of toxic compounds resulting fromthe combustion of a fuel to vapourize the working liquid in the powerplant of the invention can be minimized to a negligible extent becausethe arrangement for heating the evaporator can be selected desiredly andbecause the combustion of the fuel takes place at an atmosphericpressure. The

power plant according to the invention is, therefore. expected tocontribute to the solution of the vehicular air pollution roblems.

What is claimed is:

I. A vapour power plant driven with a working fluid vapou rized fromcool liquid including trichromonofluoromethane having a freezing pointlower than minus 30' C and a boiling point lower than C. comprising aworking fluid circuit including an evaporator for vapourizing said coolliquid into a vapourized working fluid, a regulator valve disposedbetween said evaporator and a prime mover for adjusting the flow of saidvapourized working fluid to be fed to said prime mover, a cooling fluidcircuit including a cooling means, said working fluid and cooling fluidcircuits sharing a common condenser communicating with the outlet portsof said prime mover and said cooling means and a common liquid reservoircommunicating with the inlet ports of said evaporator and said coolingmeans, said working fluid circuit having a first pump interposed betweensaid reservoir and said evaporator, and said cooling fluid circuithaving a second pump interposed between said reservoir and said coolingmeans, whereby said cool liquid in said reservoir is passed by saidfirst and second pumps over to said evaporator and to said coolingmeans, resfectively.

. A vapour power plant driven with a working fluld vapourized from coolliquid including trichromonofluoromethane having a freezing point lowerthan minus 30 C and a boiling point lower than 95 C, comprising anevaporator delivering a vapourized working fluid, a prime movercommunicating at its inlet port with said evaporator for receiving thevapourized working fluid therefrom, a regulator valve disposed betweensaid evaporator and said prime mover for adjusting the flow of saidvapourized working lfuid to be delivered to said prime mover a vapourcondenser communicating at its inlet port with an outlet port of saidprime mover for receiving and liquefying an exhaust dischargedtherefrom, a liquid reservoir communicating at its inlet with saidcondenser for temporarily storing a cool liquid fed therefrom andcommunicating at outlet port with an inlet port of said evaporatorthrough a first pump interposed between said reservoir and said boilerand a cooling means communicating at its inlet port with a second outletport of said reservoir through a second pump and at its outlet port witha second inlet port of said condenser, said first and second pumpfeeding said cool liquid in said reservoir to said evaporator and saidcooling means, respectively, the liquid forcedly cooled in said coolingmeans being fed into said condenser for cooling and liquefying theexhaust discharged from said prime mover in the succeeding cycle.

i i i i I

2. A vapour power plant driven with a working fluid vapourized from coolliquid including trichromonofluoromethane having a freezing point lowerthan minus 30* C and a boiling point lower than 95* C, comprising anevaporator delivering a vapourized working fluid, a prime movercommunicating at its inlet port with said evaporator for receiving thevapourized working fluid therefrom, a regulator valve disposed betweensaid evaporator and said prime mover for adjusting the flow of saidvapourized working fluid to be delivered to said prime mover a vapourcondenser communicating at its inlet port with an outlet port of saidprime mover for receiving and liquefying an exhaust dischargedtherefrom, a liquid reservoir communicating at its inlet with saidcondenser for temporarily storing a cool liquid fed therefrom andcommunicating at outlet port with an inlet port of said evaporatorthrough a first pump interposed between said reservoir and said boilerand a cooling means communicating at its inlet port with a second outletport of said reservoir through a second pump and at its outlet port witha second inlet port of said condenser, said first and second pumpfeeding said cool liquid in said reservoir to said evaporator and saidcooling means, respectively, the liquid forcedly cooled in said coolingmeans being fed into said condenser for cooling and liquefying theexhaust discharged from said prime mover in the succeeding cycle.